Currently, electrical devices with a lighting module have been widely used by people. Taking liquid crystal displays (LCDs) for example, with their advantages of high image quality, compact size, light weight, low driving voltage, low power consumption and various applications, LCDs have been introduced into various electrical products, such as portable computers, mobile phones, personal digital assistants and color televisions.
Normally, an LCD includes a liquid crystal display panel and a backlight module. The backlight module is configured to provide a light source to the liquid crystal display panel for displaying image. It is understood that a conventional LCD may include a photo-sensor for detecting the surrounding light intensity and for adjusting the brightness of the backlight module according to the detecting result of the photo-sensor, thereby saving energy.
However, the electrical device which can detect the surrounding light intensity, such as an LCD, needs an additional photo-sensor, and thus the cost thereof is increased. Furthermore, if the photo-sensor is disposed on the exterior of the electrical device, thereby the electrical device needs a case with an opening for accommodating it; therefore, the design appearance of the electrical device needs to be changed, and the cost thereof is also increased.